For a three-dimensional memory device including a plurality of electrode layers stacked on a substrate, a structure has been proposed in which metal layers are formed as the electrode layers, and an air gap is further made between the metal layers adjacent to each other above and below. The air gap is made by removing sacrificial layers after the metal layers and the sacrificial layers are stacked alternately. There are cases where it is desirable to appropriately combine the material of the metal layer and the material of the sacrificial layer for the processes and device characteristics.